To document snowmobile starter mounting-hole spacing, identify the exact two hole centers used for every dimension and state which end of the starter the drawing shows. Label each mounting feature individually, distinguish holes from studs, and include the terminal orientation so the supplier can interpret the pattern without guessing.
These instructions apply only to an already removed, non-energized starter. They do not cover removal, electrical testing, disassembly, or installation.
Define the view before labeling the centers
Use a mounting-face sketch or photograph as the reference view. Give it an explicit caption, such as “Viewed from the drive end, looking toward the motor body,” if that accurately describes the image. If the opposite end is shown, say so instead. Avoid labels such as “front view” without explaining which end is meant.
On that same view:
- Identify the shaft or drive end.
- Mark the terminal location where visible; use a separately labeled side view if necessary.
- Label the mounting features A, B, C, and D as applicable.
- Use those same labels on the photographs and measurement record.
If one view does not show all mounting features clearly, add another view and identify its direction. Do not silently combine dimensions taken from opposite sides into one unlabeled sketch.
Specify which centers each dimension connects
Two mounting features
For a two-hole arrangement, label the holes A and B and identify the requested dimension as “A–B, center to center.” Record each hole's diameter separately; a hole diameter is not the spacing between holes.
For a stud-mounted arrangement, identify the stud axes rather than calling them through-holes. The supplied 0745-052 information, for example, describes two 5/16-18 mounting studs—not two clearance holes.
More than two mounting features
Label every mounting feature, then identify the endpoint pair for each recorded dimension. “Hole spacing” by itself is not a sufficient label for a multi-hole pattern.
Do not assume that a four-bolt arrangement is a rectangle or that one spacing describes the entire pattern. The supplied information describes 0745-444 with a four-bolt arrangement of 2+2 and 0745-441 with an arrangement of 2+1+1; neither entry supplies verified hole spacing or mounting angles. Preserve the actual layout in the sketch and ask the supplier which additional dimensions are needed.
Different hole types
Record the type of each labeled feature. This matters when a mounting pattern contains unlike features: the 420684560 reference group is described with one approximately 6 mm unthreaded hole and one M8×1.25 threaded hole. A drawing that calls both simply “mounting holes” loses useful information.
Keep measurements separate from catalog descriptions
For each measurement on the removed, non-energized part, record:
| Record field | What to identify |
|---|---|
| Feature pair | The labeled centers, such as A–B |
| Dimension meaning | Center-to-center spacing, not edge-to-edge distance |
| Units | Explicitly state mm or inches |
| Origin | Measurement of the reference part, supplier drawing, or catalog description |
| Status | Measured, confirmed by supplier, or unconfirmed |
If you cannot establish the centers reliably, leave the center-to-center value unconfirmed rather than relabeling an edge measurement as center spacing.
Catalog wording also needs care. The 3020-364 entry lists approximately 40 mm mounting-ear spacing, while 7902-987 lists approximately 55.9 mm mounting-ear spacing. Those descriptions do not explicitly define the measurement endpoints. Do not turn either value into a confirmed hole-center dimension without clarification.
A photograph can document visible features, but it is not a scale drawing. Keep the labeled image and the dimension record together rather than asking the supplier to infer spacing from image proportions.
Send a drawing with clear limits
Include the original part marking, exact machine model and established model year, drawing date, and revision. State which dimensions came from the reference part and which remain unresolved.
Do not add an assumed plus/minus tolerance or treat an approximate catalog value as an acceptance limit. No mounting-hole spacing tolerances are established by the supplied information. Ask the supplier to confirm the dimension definitions, required additional views, and applicable tolerances on its proposed drawing.
The finished record should let the supplier answer a specific question: Does the proposed starter have the same identified mounting pattern, viewed in the same direction? That confirmation supports a mounting review; it does not by itself establish complete replacement snowmobile starter fitment.